Improvement in paddle-wheels



F. W. BARDWELL.

PADDLE-WHEEL.

No.175,405, Patented March 28,1876.

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UNITED STATES PATENT QFFIGE.

FREDERIO W. BARDWELL, OF LAWRENCE, KANSAS.

IMPROVEMENT IN PADDLE-WHEELS.

Specification forming part of Letters Patent No. 175,405, dated March28, 1876; application filed October 28, 1875.

To all whom it may concern:

Be it known that I, FREDERIG W. BARD- WELL, of Lawrence, in the countyof Douglas and State of Kansas, have invented a new and useful Form ofWheel for Propelling Steamers, the construction of which is fullyexplained in the following specification and accompanying drawing:

The object sought in this invention is to avoid the loss of power,which, in the operation of the ordinary paddle-wheel of a steamer,results from, first, the sudden impact of the paddle striking the water;secondly, the lifting of the water by the paddles as they rise above thegeneral water'level; and, thirdly, the violent agitation of the water,in causing which power is necessarily consumed.

In Figure l of the accompanying drawing the form of the wheel is shownin perspective; and in Fig. 2, a section perpendicular to the axis ofthe wheel at its middle point, cutting the outer surface of the wheelalong the broken line i k, as seen in Fig. 1.

Upon the surface of a closed cylinder (or of a surface of revolutionapproaching the cylinder in form) a series of plane surfaces, calledtraction-faces, extend outward, like the paddles of the ordinarypaddle-wheel. In Fig. l, c c n n is one of the traction-faces.

Another series of surfaces extend from the extremities of thesetraction-faces forward, and become tangent to the closed surface of thecylinder or other surface of revolution, as

- the case may be, thereby shielding the traction-faces from impact asthey enter the water. In Fig. 1, n a 0 o is one of the tangent surfaces,extending from the extreme edge of one traction-face forward, andmeeting the closed surface at the foot of the next traction-face. Thistangent surface is a plane in case the closed surface is a cylinder,otherwise it must be curved according to the curvature of the closedsurface.

The essential character of the construction is most easily apprehendedat first by supposing the closed surface to be a cylinder; but,obviously, more efficient action of the wheel would result by making thesection along the line i k deeper than that along the outer line, sothat while the middle point of the edge of a traction-face, as m,extends the farthest below the water-level, the points 0 r and c of thesame edge reach only a little way below.

The arrow at indicates the direction of rotation of the wheel, while thearrow 1) shows the forward motion through the water.

Operation: The moment a traction-face becomes submerged the water ispressed against it, and in the motion of the wheel this face cannot beseparated from the water immediately in front, nor can that waterimmediately in front be drawn backward without entraining with it waterstill farther in front to an indefinite extent. The closed surface ofthe wheel tends to prevent displacement of the water, and therebypromotes the success of the action in question, so that the tractionfaceis retained in its place in the water more effectually than is possiblefor the paddle of the ordinary wheel, and the power applied to turn thewheel operates more efficiently in causing the boat to move forward.

Dzfierencea-In the ordinary paddle-wheel the power is exerted by theimpact of the paddles striking the water and pushing against the waterbehind it, while in the tractionwheel it is a special object to avoidboth impact and pushing, and, instead, draw upon the water in front.

Adoantages. Thus there is no loss of power from impact, aminimum of lossby water carried upward on the periphery of the wheel, and a minimum ofloss of power expended in the agitation of water.

It is also often very desirable, in the case of canals and small rivers,to avoid the disturbance of water caused by paddles of steamboatwheels,both on account of injury to the banks, and, in the case of rivers, theannoyance to small boats.

Although the greatest advantages to be derived from the traction-wheelare expected in the case of high speed, yet, in actual experiments ofusing alternately the two kinds of wheels upon the same boat, making thetrial as equitable as possible, the best results, even similar surfaceof revolution, with radial sut with low rates of speed, were gainedwithzthe l'aces extendingvoutward to meet tangent surtraction-wheel.faces, either plane or curved, which extend The closed surface of thewheel, making the forward, substantially as described. interior like ahollow drum, is not supposed FREDERIG W. BARDWELL. to be new; butWitnesses:

I claim as my invention DANIELAR ENGLISHQ The combination of a closedcylinder, or a GEO. E. PATRICK.

